Split seconds stop watch



(No Model.) 2 Sheets-8heet 1.

G. H. MEYLAN.

SPLIT SECONDS STOP WATCH.

No. 888,749. Patented May 29, 1888.

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2 Sheets-Sheet 2.

(No Model.)

0. H. MEYLAN.

SPLIT 3300mm STOP WATCH.

No. 383,749. Patented May 29, 1888.

Unrrnn STATES PATENT (lenient CHARLES H. WIEYLAN, OF NEW YORK, N. Y.

SFLiT=-ECGNDS STOP 'WATQl'i.

EBPLCIFICATION forming part of Letters Patent No. 383,749, dated May 29,1 888.

Application filed August 3i, 186:7.

To aZZ whom it may concern:

Be it known that 1, CHARLES HENRY MEY- LAN, of the city and State of NewYork, have invented an Improvement in Split Seconds StopWVatchesoi'which the followingis aspect fieation.

XVatches have heretof re been made with a mechanism that connects thewheels in the ordinary movement to an independent secondshand that isunder the control of stop mechanism and apush-lever, so that when thepushlever is actuated the iirst time the independent seconds'hand isstarted, and it is moved by the time-gearing. The second push of the levcr stops the independent seconds-hand, and the third push of the leverrot-urns the independent seconds-hand to zero or twelve, ready to beagain started. \Vatches of this character are usually known asstop-watches, and a reference is hereby made to Letters Patent No.235,794, granted to me December 21,1880, and which shows astop-movementwith which my presentimprovements are especially available.Vatches have also been made for tak' ing two observations, but they haveusually been provided with second stop-movement, and have beencomplicated and expensive.

Efliorts have been niadeto construct watches with two seconds-hands oneon a-central arbor and the other upon a tubular arbor around it--withclamping-fingers for holding one hand while the other continues to move;but diiiiculty has been experienced in properly moving the ordinary hourand minute hands, because a pinion was made use of that was independentof the train of gearing and received its movement from the gear-wheel onthe springbarrel and the hands were liable to shake or swing inconsequence of looseness in the teeth and from being uncontrolled by anyconnection in the train to the balance.

I construct the stop-Watch mechanism as hereinafter described andconnect the ordinary hour and minute hands to the train of gearing insuch a man nor that looseness is p re vented and the hour and minutehand arbors are concentric with the two arbors of the split orindependentseconds-hands ofthestop mech anism.

In the drawings, Figure 1 shows the stopwatch movement corresponding tothat shown Sci inl No. l7. (No model.)

in my patent, No. 235,79i,only it is by proton ence placed upon the backplate of the watch instead of beneath the face. Fig. 2 is a section atthe line a: a", Fig. 3. Fig. 3 is an elevation of the mechanismconnected with the additional seconds hand,the facehands and hour andminute gears being removed. Fig. at is a rear view of the skeleton wheeland the mechanism detached; and Fig. 5 is a section in greatly-magnifiedsize of the end portions of the two tubular arbors, showing the frictiondevice for connecting them.

A reference is hereby made to my aforesaid patent for a description ofthe parts shown in Fig. 1 and the mode of operation of the same, theletters of reference corresponding thereto. I, however, remark that thecenter arbor of the watch in this instance is supported by the bridge Aupon the back plate, B, of the watch.

The center arbor, f, of the watch passes through the tubular arbor ofthe center wheel in the ordinary time-train of the watch. Upon the rearend of the arbor f is the heartcam 1' and wheel a, (shown in myaforesaid patent,) and upon the other end of this arborfis theindependent seconds hand 2. The wheel a on the arbor b of the ordinaryseconds-hand and the wheels in a are the same as in my aforesaid patcnt,and the swinging arm Z and mechanism for moving the n heel or instarting the independentseconds hand upon the first push of thepush-lever h, and the means for stopmal or Zero position, are the sameas in said patent.

Upon the arbor f is a second heartcam, 4-, and around the arbor f is atube, 5, forming the arbor of the skeleton wheel (hand also receiving atthe other end the additional secondshand,7, and there is aspring-finger, 8, the end of which acts against the heartcam 4, and whenthe parts are in a normal position this springiinger causes the twoseconds-hands 2 and 7 to coincide, because the spring '-finger slidesupon the edge of the heart-cam,turning the skeleton wheel arbor 5 andhand 7 untilv the end of the spring-finger reaches the inner part of theheart-cam, the hands coinciding when the parts reach this position.

To stop the independent or split seconds, I

ping the hand and for returning it to the normake use of theclampingfingers 10, pivoted at 11 and standing at opposite sides of theskeleton wheel 6. The spring 12 tends to close these fingers and clampthe skeleton wheel and the rotary spur-cams 13,acted upon by theratchet-wheel 14, push -lever 15, and pawl 16, are employed to open theclampingfingers and release the skeleton wheel 6 every second movementof the push-lever. A convenient way of making the spur-cams 13 is tofile away the lower points of the alternating ratchet-teeth of the wheel14, as seen in Fig. 4. It will now be understood that when thepush-lever h is acted upon the arbor f will be connected to the arbor bof the ordinary seconds-hand of the watch, and said arborfand theseconds-hand 2 will rotate in unison with the ordinary seconds-hand, andthe additional secnds-hand, 7, will travel along with and be immediatelybelow the hand 2. \Vhen an observation is to be noted, the push-lever 15is acted upon and the skeleton wheel 6 grasped, stopping the hand 7instantly; but the hand 2 continues its movement with but littlefriction except that which results from the heart-cam 4 turning incontact with the spring-finger 8. When a second observation is to bemade,the

push -1ever h is acted upon, the wheels at n are thereby separated, andthe brake 0 applied to the edge of the wheel a, which stops the arbor fand hand 2. The third push on the lever it returns the hand 2 to itsnormal position,and the additional seconds-hand, 7, is made to coincidewith the hand 2 by the action of the heart-cam 4 and spring finger 8either before or after acting upon the pushlever h.

In stop-watches containing a split or independent seconds-handdifficulty has heretofore been experienced, as before mentioned, inpre-..

venting looseness of the ordinary hour and minute hands when the arborsof such hands are concentric with the split or independent seconds-handsand in the center of the watch, because the pinion that moves the handshas I not been in the time-train itself, and hence there was nothing tokeep the teeth together at one side, and the looseness inseparable fromthe teeth of the wheels was manifest by the hands shaking or swinging,sometimes as much as one or two. minutes. I prevent this difficulty bymaking the arbor 31 of the center wheel, 32, and pinion 33 in thewatch-movement as a tube, and passing through the same the tubular arbor34, that is formed with or permanently connected to the gear-wheel 24,and this tubular arbor 34 is held withinthe arbor 31 by friction, theend 35 of the arbor being recessed conically and receiving theslightly-flaring conical spring end of the tubular arbor 34, so that thetwo arbors will turn together; but the arbor 34 can be turned within thearbor 31 when setting the hands. The solid arborf, be-

fore described, is within this tubular arbor34, and is pivoted at oneend in the bridge A and supported byan inward collar, 36, within thewheel 24, that forms a bearing for the arbor f and prevents any endmovement thereof. The heart-cam 4 is driven upon this arborfoutside thewheel 24, and is held firmly by friction hence the heart-cam 4 acts'withthe wheel '6 and spring-finger 8, and the two independent orsplit'seconds hands do not prevent the connection being taken from thewheel 24 through the wheel 23 and wheel 22 to the wheel 37 on the arbor20 of the minute-hand 21, and from the pinion 26 to the wheel 27,tubular arbor 2S, and hour-hand 29. The arbor of the wheels 22 and 23passes through the bridge 18 into the watch-plate, and the wheel 23 isbelow said bridge, and the intermediate wheel 30 upon the watch-plate isacted upon by the gear-wheel on the swinging plate in an ordinary stemwinding and setting mechanism, so that the wheels 23 and 24 and thegearing to the hands and the hands themselves can be moved in settingthe watch, as usual; but the tubular arbor 34 is turned in the tubulararbor 31 when setting the hands, and there is no risk of looseness inthe hands, because the wheel 24 is entirely under the control of thetime-train of the watch.

I claim as my invention 1. The combination, in a stop-watch, of thearborf for the independent seconds-hand, the tubulararbor 5for theadditional independent seconds-hand, the bridge 18, tubular arbor 19,cannon 20 for the minute-hand, wheel 27, and cannon 28 for thehour-hand, the gear-wheel 23 and pinion 24 for driving the hour andminute hands, and the gearingconnecting the arbor of the wheel 24 withthe train of gearing in the watch movement, substantially as specified.

2. The combination, with the tubular center arbor, 31, in awatch-movement, of the tubular arbor 34, passing through the arbor 31and held therein by friction, the wheel 24 on such arbor 34, the hourandminute hands and their tubular arbors, and the gearing between the wheel24 and such hour and minute hands, and an arbor passing through thearbor 34 and carrying an independent seconds hand, substantially as setforth.

3. The combination, with the tubular central arbor, 31, in awatch-movement, of the tubular arbor 34, passing through the centralarbor,31,and held therein by friction, the gearwheel 24'on such arbor,the hour and minute hands and their gearing, and an independentseconds-hand, 2, and central arbor, f, therefor within a bearing insidethe tubular arbor 34, a bridge, A, for one end of said arborf, and theconnections formoving the said arborf and hand, substantially as setforth.

Signed by me this 26th dayof August, 1887.

O. H. MEYLAN.

Witnesses:

GEO. T. PINCKNEY, CHAS. H. SMITH.

